Pneumatic tire.



'RRONDEAU PNEUMATIG '.I'IBE. APPLIoATIoR funn 113.1, 1911.

Patented NOV. 25, 1913.

REN RONDEAU, or PARIS, FRANCE,

AssIGNon To SOCIT FERMIREDE LAUTOMATIQUE DUCASBLE, 0F PARIS, FRANCE.

PNEUMATIC TIRE.

Specification of Letters Patent.

Patented Nov. 25, 1 913.

Application led February 7. 1911. Serial No. 607,168.

ITo all whom 1'25 may concern invented a new and useful Improvement iii Pneumatic Tires, which improvement is fully set forth in the following specification.

This invention relates particularly `to iinprovements upon pneumatic tires of the type illustrated in French patent to Du casble No. 7,099 of March 12, 1907, second addition to F rcnch Patent No. 326,018, in which type oi tire an annulus of indiariibber is provided internally With hollow cham bers or cells'in free communication With the atmosphere presenting the advantage, as compared with ordinary pneumatic tires, of not puncturing or bursting. Nevertheless, this form of tire presented certain inconveniences which have prevented its wide adoption for automobile purposes. Firstly.l the thickness of indiarubber surrounding the inner chambers or cells was not uniform, presenting a maximum thickness in the longitudinal axis of the tire and a minimum thickness transversely of said axis. In-particular it might be considered that the original form ot the tire was constituted in horizontal section by circulai` thicknesses of indiarubber, the outer part of which was sectiened laterally and tangentially to the point. of connection of the several elements, one with the other. This tire, therefore, 'pixeieiltcd a riester thickness in the plane the treat"L :it points between the cells or chambers, or in other words hard and less pliable points than the parts located beneath the cells. Then again at these points the tire was much weakened laterally by the deep lateral recesses, the most hollowed portions of which were situated beneath the center of the chambers so that the tire was also weakened. toward its tread circle which rendermi, it very readily deformable transversely. the result of this' peculiarity in its cenioriiiation was that the tire While presenting a series of'hard points on its p eriphery yielded at high speeds and oscillated around its vertical position in becoming inclined which produced a slight rolling of the. rear Wheels such as takes place when ordinary compressed air pneumatic tires are somewhat deated.

.y The improved pneumatic tire which forms the object of this invention obviates this defect o-wing to the fact that the material is distributed in an absolutely uniform and rational manner relatively 'to the inner chambers or cells and to the lateral recesses.

The novel pneumatic tire is represented iii Figure 1 in section on the line X X Fig. 2; Fig. 2 in vertical section on the line Y Y in Fig. 1,; and in Fig. 3 in partial side elevation. t Y

As shown in these figures the thickness of india-rubber surrounding the cells is absolutely uniform because in the section X' X, Fig. 1, the thickness a is constant both laterally and between two consecutive cells and in the vertical section Y Y in such a manner that the tire can no longer be considered as constituted of separate elements connected up one With the other` but as an absolutely homogeneous Whole. With this object the cells e have been suitably brought together in such a-manner that the outer cir.- cles c 0 instead of being tangential one to Z.v The transverse dimensions C of the chamber and its `height d are also selected in such a manner that the thickness a is approximately constant .and the lateral recesses (l are raised relatively to the tread surface in such 'a manner that they are Lat the same height as the cells' e and their most hollowe'd portion approximately coincides in height wit the center of the cells e. In addition thei rdepth by is calculated in such a manner` as to maintain the thickness a constant in the plane of the horizontal section passing through the Widest part ot' the cell. The tire is thus divided in the direction of its height into three zone each serving an absolutely distinct puhp se. A tread band comprises between the ground and the lower part of the cells and on the outer recesses which transmits to the flexible zone the powerful shocks that it has been unable to absorb. (2) The zone of ilexibility comprising t'he Whole of the efective height of the cells and of the lateral recesses which absorbs all the important shocks 0W- di-rection Vand to the operation of the free air cells. (3) The' base of the .tire serving `rto support it upon the -rim and [ixl it thereto. Finally, the form of the tire in section is that of 'a t'eapesium with slightly curved or the other are tangentialto the inner circles ing to its ready deformation'in the vertical rectilinear s1des."the iargest base being ein- 110 I2 i bedded in a metal rim g with flat lateral \langes h rising sufficiently to embrace the base of the tire and aprevent it from oscillating without weakening this base in any way.

It will, of course, be understood that the lateral form of the recesses may vary provided that the conditions set forth above are met and the chambers e are not only able to communicate :freelA with the air through the passages m but :iso one with the other indiscriminately or in groups. The tread surface may also be provided with transverse channels z' and with one or more fongitudinal channels y' or with metal rivets in order to provide a non-skid surface.

What is claimed is :4-

A wheel tire consisting of an annular body of rubber having in lts interior a succession of chambers or cells in communication with the atmosphere and at its exteriol in cach of its side walls a succession of recesses, the interior chambers and the exterior recesses. being of such shape and relative location that if an annular section is made of the tire in the portion of the chamber of greatest section the thickness of the rubber 1s' uniform both on the sides of the tire and between the succeeding cells cr chambers and that in the case of a cross section through the cells the thickness of the rubber wall about the cell is substantiallyY constant.

In witness whereof I have hereunto set my hand in presence of two witnesses.

REN RONDEAU.

Witnesses DEAN B. MASON, ALBERT Brno 

